Ecosystem effects
IMARES has broad expertise concerning the possible effects of various types of fisheries on the ecosystem. We have a wealth of data originating from ongoing programmes, where independent observers travel on fishing vessels. We also maintain a database with information on undesired bycatch, such as birds and fish. We supplement this information with experiments conducted on the research ship OV “Tridens” (see adjacent photograph) and on commercial fishing vessels in order to measure the effects of different types of fishing nets on benthic animals and the composition of fish populations. Moreover, we work on models that can be used to explain and predict changes in the ecosystem.
Ecosystem dynamics
Marine ecosystem research is challenged by the following questions: How can the interaction between fisheries, pollution and climate variations affect the state of ecosystems? What are the internal dynamics of the systems themselves? To answer these questions, an integrated approach is required. This is partly because the progression in the numbers of fish is not only determined by the fishery, but also by food availability for larvae, predation, temperature, habitat conditions and the transport of eggs and larvae. Understanding these processes requires an ecosystem approach that investigates their relationships, is open to the combination of bottom-up and top-down forces and pays attention to the occurrence of regime shifts.
Priorities within this theme include research into the dynamic ecosystem, sustainable exploitation of marine biota, protection of marine ecosystems and multifunctional spatial use. The research topics include natural and human-caused changes, unravelling the effects of fisheries and climate on marine ecological communities, factors that determine the numbers of top predators, the dynamics of commercially exploited fish and shellfish stocks and of fishery systems, the spatial dynamics and biodiversity of non-motile marine fauna, and shifts in spatial use in the coastal zones and floodplains and their effects on the dynamic ecosystem.